Vessel treatment devices

ABSTRACT

A catheter system for treating lesions is provided. The system is suitable for treatment of bifurcation lesions, has a low profile and provides substantially predictable translational and rotational positioning. In one embodiment, the system includes a fixed wire balloon catheter and a partially attached guidewire lumen, wherein the guidewire lumen is attached to the catheter at a crotch point. The location of the crotch point is predetermined so as to provide substantially predictable positioning. Several embodiments of the system are described for various types of lesions and vessel configurations.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/431,918, filed May 11, 2006, which is a continuation-in-part of U.S.patent application Ser. No. 11/240,631, filed Oct. 3, 2005, which is acontinuation-in-part of U.S. patent application Ser. No. 11/070,294,filed Mar. 3, 2005, which is a continuation-in-part of U.S. patentapplication Ser. No. 10/899,034, filed Jul. 27, 2004, which claims thebenefit of U.S. Provisional Application No. 60/549,554, filed Mar. 4,2004, all of which are incorporated herein by reference in theirentireties.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to vessel treatment devices and methodsand, more particularly, to catheter systems having low profiles andpredictable positioning capabilities, both rotationally andtranslationally.

Several problems are associated with known prior art stent deliverydevices, particularly ones which are suitable for treating bifurcationlesions. First, they generally have large outer diameters, particularlysince the known designs usually include two guidewire lumens—one for amain guidewire and one for a side branch guidewire. The relatively largeprofiles of currently known systems cause difficulties inmaneuverability and access to the site. Furthermore, the presence of twoguidewires often results in wire entanglement, making the proceduredifficult to perform without multiple insertions and retractions.Another problem which persists in these devices is inaccuratepositioning within the vessel. This problem has been addressed with theuse of radiopaque markers placed in strategic locations. However,visualization is done in the two-dimensional plane, while the actualprocedure takes place within the three-dimensional realm. As such,inaccurate deployment is commonplace, often resulting in either stentjailing or insufficient coverage.

An example of a prior art bifurcation stent delivery system is disclosedin U.S. Pat. No. 6,048,361 to Von Oepen. The system includes a stentwith an increased radial opening and a balloon catheter on which thestent is mounted, the balloon catheter having a hollow chamber forpassage of a guiding wire so that it exits in a center of the increasedopening. The system disclosed therein includes two passageways forguidewires, necessitating a relatively large outer diameter.Furthermore, the presence of two wires can lead to problems of wireentanglement.

Other examples of prior art bifurcation stent delivery systems andmethods are disclosed in U.S. Pat. No. 6,692,483 to Vardi et al. andU.S. Publication Number 2001/0049548 to Vardi et al. These include aballoon catheter having a main guidewire lumen and a flexible sidesheath having a side branch lumen. The method disclosed aims to reducewire entanglement by first inserting one of the guidewires, thenadvancing the system, and finally advancing the second guidewire.Alternatively, one of the guidewires is housed within the system andonly released once the system is in place. However, problems of wireentanglement may also occur upon removal of the system. Furthermore, thesystem disclosed therein is prone to overshooting of the bifurcation,resulting in sub-optimal placement. Finally, the dual lumenconfiguration results in a relatively large profile for the overallsystem.

Other similar examples of prior art bifurcation stent delivery systemsare disclosed in U.S. Pat. No. 5,749,825 to Fischell et al. and U.S.Pat. No. 6,682,556 to Ischinger. The systems disclosed therein includeballoon catheters with side branch tubes, and require two guidewires:one for the main vessel and one for the branch vessel. Similar to theaforementioned prior art, large profile, wire entanglement, andinaccurate positioning are potential problems.

A prior art device which aims to provide improved rotational orientationwhile avoiding wire entanglement is disclosed in U.S. Publication Number2003/0055483 to Gumm. Gumm discloses a catheter assembly having arotatably mounted balloon, and further including a side branch hollowmember attached to the catheter balloon. A noted feature of the deviceis the use of rotating members sealed to opposite ends of the balloon.Thus, the side branch hollow member, the balloon and the rotatingmembers act as a unit which rotates freely relative to the mainhypotube. This particular feature is considered an integral part of thedesign, providing improved orientation of the stent relative to the sidebranch at the bifurcation. However, this feature also results in anincreased overall diameter of the system. Furthermore, it does notprovide a way to accurately position the stent in the translationalplane.

Attempts have been made to reduce the profile of a single stent deliverydevice by using a fixed wire balloon catheter, such as is disclosed inU.S. Publication Number 2002/0147491 to Khan et al. The device disclosedtherein includes either a short section of guidewire fixedly attached tothe distal end of a balloon, or a core wire that extends within thesystem. This design reduces the profile of the system as compared toprior art devices by eliminating the inner guidewire lumen. However, thesystem disclosed therein does not teach or suggest the possibility ofbifurcation stenting, nor does it provide rapid exchange capabilities.

There is thus a widely recognized need for, and it would be highlyadvantageous to have, a stent delivery system devoid of the abovelimitations.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a catheter systemincluding a catheter body with a catheter proximal end and a catheterdistal end, a balloon positioned on the catheter distal end, the balloonhaving a balloon proximal end and a balloon distal end, a guidewirelumen attached to the balloon distal end, the guidewire lumen having alength of less than 15 mm, and a guidewire enclosure having an enclosuredistal end and an enclosure proximal end, and at least partiallyattached to the catheter body.

According to further features in preferred embodiments, the cathetersystem further includes a stent positioned on the balloon. The stent haseither a dedicated side opening or regular openings, and the enclosuredistal end is positionable at or through the side opening or openings.In a preferred embodiment, the balloon in its deflated configuration hasa temporary lumen for receiving a guidewire therethrough, and thetemporary lumen is preferably longitudinally aligned with the guidewirelumen, such that a distal end of the guidewire is positionable throughthe guidewire lumen and a portion of the guidewire which is proximal tothe distal end of the guidewire is positionable in the temporary lumen.According to further features, the balloon in a deflated configurationhas an “S” shape having an upper curved portion and a lower curvedportion, wherein the lower curved portion is a containment area forholding a guidewire therein. In alternative embodiments, the balloon ina deflated configuration has a hooked “Y” shape, wherein a bottomportion of the “Y” shape is hooked so as to form a containment area forholding a guidewire therein. The “Y” shape may further include two upperarms which form a secondary containment area for holding the guidewireenclosure therein. In a preferred embodiment, the temporary lumen andthe guidewire lumen are on an opposite side from the guidewireenclosure. According to additional features, the guidewire enclosure isat least partially positioned within the catheter body and is attachedto the catheter body at a location on the balloon. The location ofattachment is approximately in a center of the balloon.

According to a further aspect of the present invention, there isprovided a method for treating a lesion in a vessel. The method includesproviding a catheter system having a catheter body with a balloon on adistal end thereof, a guidewire lumen attached to a distal end of theballoon, a guidewire enclosure at least partially attached to thecatheter; and a guidewire positioned through the guidewire lumen andthrough a temporary lumen in the balloon such that the guidewire isimmovable with respect to the catheter body, introducing a trackingguidewire having a distal end and a proximal end into the vessel,positioning the proximal end of the tracking guidewire in the guidewireenclosure, advancing the catheter over the tracking guidewire until thecatheter reaches the lesion, and inflating the balloon thereby releasingthe guidewire from the temporary lumen.

According to yet another aspect of the invention, there is provided acatheter system including a catheter body having a catheter proximal endand a catheter distal end, a fixed wire balloon positioned at thecatheter distal end and having a working length portion having asubstantially uniform diameter, a proximal narrowed portion proximal tothe working length portion having a smaller diameter than thesubstantially uniform diameter of the working length portion, and adistal narrowed portion distal to the working length portion having asmaller diameter than the substantially uniform diameter of the workinglength portion, and a guidewire enclosure having an enclosure proximalend and an enclosure distal end, the guidewire enclosure at leastpartially attached to the catheter at an attachment point, wherein theattachment point is located proximal to said working length portion ofsaid fixed wire balloon.

According to further features in preferred embodiments of the presentinvention, the guidewire enclosure is at least partially positionedwithin the catheter body. The attachment point is at or proximal to theenclosure distal end. In one preferred embodiment, the catheter systemfurther includes a guidewire positionable within the guidewireenclosure. According to further features, at least a portion of thecatheter body is comprised of a rigid material thereby providing a rigidcontrol area, and the catheter system further includes a substantiallyrigid core wire positioned through the fixed wire balloon and connectingthe balloon distal end and the rigid control area.

According to yet another aspect of the present invention, there isprovided a method for treating a lesion in a vessel. The method includesintroducing a guidewire into the vessel and through the lesion,providing a catheter having a fixed wire balloon and a guidewireenclosure attached to a proximal end of the fixed wire balloon,introducing a proximal end of the guidewire into the guidewire enclosureof the catheter, advancing the catheter over the guidewire until adistal end of the catheter is at the lesion and the guidewire ispositioned alongside the balloon, and inflating the balloon so as tocompress the guidewire into the lesion.

In one embodiment, the method further includes treating a lesion in asecond vessel, the second vessel being connected to the first vessel ata bifurcation. The method includes at least partially deflating theballoon, retracting the catheter along the guidewire, introducing thecatheter into the second vessel, and inflating the balloon.

According to yet another aspect of the invention there is provided amethod for treating a first lesion in a first vessel and a second lesionin a second vessel, the first and second vessel connected at abifurcation. The method includes introducing a guidewire into the secondvessel, providing a catheter having a fixed wire balloon and a guidewireenclosure attached to a proximal end of the fixed wire balloon,introducing a proximal end of the guidewire into the guidewire enclosureof the catheter, advancing the catheter over the guidewire until adistal end of the catheter reaches the bifurcation, further advancingthe catheter past the bifurcation and into the first vessel such thatthe balloon is positioned alongside the first lesion, inflating theballoon, deflating the balloon, retracting the catheter over theguidewire, introducing the catheter into the second vessel, such thatthe guidewire is positioned alongside the balloon, and inflating theballoon so as to compress the guidewire into the second lesion.

According to yet another aspect of the invention, there is provided amethod for treating an intracranial aneurysm in a vessel. The methodincludes providing a catheter having a fixed wire balloon, an auxiliaryelongated element at least partially attached to the balloon, and astent positioned on the balloon and having a side opening, wherein theelongated element is positioned at the side opening, introducing thecatheter into the vessel, positioning the catheter such that said theside opening is situated at the aneurysm, deploying the stent, removingthe catheter, and introducing a coil delivery system for introduction ofan embolic coil into the aneurysm.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, suitable methods andmaterials are described below. In case of conflict, the patentspecification, including definitions, will control. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, withreference to the accompanying drawings. With specific reference now tothe drawings in detail, it is stressed that the particulars shown are byway of example and for purposes of illustrative discussion of thepreferred embodiments of the present invention only, and are presentedin the cause of providing what is believed to be the most useful andreadily understood description of the principles and conceptual aspectsof the invention. In this regard, no attempt is made to show structuraldetails of the invention in more detail than is necessary for afundamental understanding of the invention, the description taken withthe drawings making apparent to those skilled in the art how the severalforms of the invention may be embodied in practice.

In the drawings:

FIG. 1 is an illustration of a first type of vessel bifurcation withplaque buildup;

FIG. 2 is an illustration of a prior art bifurcation stent deliverysystem;

FIG. 3 is an illustration of a bifurcation stent delivery system inaccordance with a preferred embodiment of the present invention;

FIGS. 4a-d are illustrations of the system of FIG. 3 shown without astent;

FIG. 5 is an illustration of the system of FIG. 3 in position at abifurcation;

FIG. 6 is an illustration of a the system of FIG. 3, shown without astent, and further including a distal connecting element;

FIG. 7 is an illustration of a bifurcation stent delivery system, shownwithout a stent, in accordance with another embodiment of the presentinvention;

FIG. 8 is an illustration of a bifurcation stent delivery system, shownwithout a stent, in accordance with yet another embodiment of thepresent invention;

FIGS. 9a and 9b are illustrations of a bifurcation stent delivery systemin accordance with another embodiment of the present invention;

FIG. 10 is an illustration of a second type of vessel bifurcation withplaque buildup;

FIGS. 11a-c are illustrations of a system for treating a bifurcationsuch as the one depicted in FIG. 10;

FIG. 12 is an illustration of the system of FIG. 11a in position at abifurcation;

FIG. 13 is an illustration of a third type of vessel bifurcation withplaque buildup;

FIGS. 14a and b are illustrations of a system for treating a bifurcationsuch as the one depicted in FIG. 13;

FIGS. 15a and b are illustrations of the system of FIG. 14, furtherincluding a holder;

FIGS. 16a and b are illustrations of the system of FIG. 14, furtherincluding a holder, in an alternative embodiment;

FIG. 17 is an illustration of the system of FIG. 14 being introducedinto a guiding catheter;

FIGS. 18a-c are illustrations of the system of FIG. 14 duringpositioning and deployment;

FIG. 19 is an illustration of a fourth type of vessel bifurcation withplaque buildup;

FIG. 20 is an illustration of a system, shown without a stent, fortreating a bifurcation such as the one depicted in FIG. 19;

FIG. 21 is an illustration of the system depicted in FIG. 20, furtherincluding stents thereon;

FIGS. 22a-d are illustrations of a method of deploying the system ofFIG. 20;

FIG. 23 is an illustration of a tapered balloon system with a sidebranch lumen, in accordance with another embodiment of the presentinvention;

FIGS. 24a-c are illustrations of different embodiments of a system fordelivery of a stent at a Type 3 bifurcation lesion or at anon-bifurcated lesion;

FIG. 25 is an illustration of the system of FIG. 24a in place at abifurcation;

FIG. 26 is an illustration of the system of FIG. 24a in place at anon-bifurcated lesion;

FIGS. 27a-d are illustrations of a configuration of markers;

FIG. 28 is an illustration of a specific shape configuration of markers;

FIGS. 29a-f are illustrations of different types of bifurcation lesions;

FIGS. 30A-30E are illustrations of steps of a method of treating anintracranial aneurysm, in accordance with embodiments of the presentinvention;

FIGS. 31A and 31B are cross-sectional illustrations of a balloon in itsdeflated state and having a guidewire positioned within a temporarylumen, in accordance with embodiments of the present invention;

FIG. 32 is an illustration of a system without a stent, in accordancewith embodiments of the present invention;

FIG. 33A is an illustration of a system without a stent, in accordancewith another embodiment of the present invention;

FIG. 33B is an illustration of the system of FIG. 33A, with a balloon inan expanded state;

FIG. 33C is a cross-sectional illustration of a portion of the system ofFIG. 33A;

FIGS. 33D and 33E are cross-sectional illustrations of another portionof the system of FIG. 33A, showing the balloon in a deflated state;

FIG. 33F is a cross-sectional illustration of the portion of the systemshown in FIGS. 33D and 33E, with the balloon in an inflated state;

FIG. 33G is a cross-sectional illustration of the portion of the systemshown in FIG. 33D-33F, with the balloon in an inflated state, accordingto another embodiment of the present invention;

FIG. 34A is an illustration of the system of FIGS. 33A-33F, adapted forover-the wire delivery; and

FIGS. 34B and 34C are cross-sectional illustrations of the system ofFIG. 34A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is of a catheter systems and methods.Specifically, the present invention can be positioned in a vessel withrotational and translational alignment. In addition to providingsubstantially predictable alignment, the devices and systems of thepresent invention have small outer diameters as compared with prior artsystems, particularly ones which are suitable for treating abifurcation, and reduce the possibility of wire entanglement.

The principles and operation of systems and methods according to thepresent invention may be better understood with reference to thedrawings and accompanying descriptions.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangement of the components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments or of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and should not be regarded as limiting.

Reference is now made to FIG. 1, which is an illustration of a vesselbifurcation with plaque buildup. A main vessel 1 and a branch vessel 2meet at a bifurcation point 3. A buildup of plaque 4 may be foundanywhere within the vessels, but if there is plaque buildup located ator close to bifurcation point 3, as shown in FIG. 1, the locationpresents a specific challenge with regard to accurate stent placement.Stents placed at bifurcations are typically deployed either slightlyproximal or slightly distal to the bifurcation point, which can lead tostent jailing and/or insufficient coverage.

Reference is now made to FIG. 2, which is an illustration of a prior artbifurcation stent delivery system 5. System 5 includes a catheter 6having a stent 7 with a dedicated side hole 8. A main guidewire 9 ispositioned in main vessel 1 and passed through a main guidewire lumen incatheter 6. A side branch guidewire 11 is positioned within a secondguidewire lumen, through side hole 8, and into branch vessel 2. As shownin FIG. 1, there is a tendency for system 5 to overshoot bifurcationpoint 3 during placement. Additionally, prior art bifurcation stentsystems are generally large in diameter due to the presence of twoguidewire lumens—one for main guidewire 9 and one for branch guidewire11. Furthermore, the two wires often become entangled with one another,causing a failure in delivery and/or removal of the system.

The present invention seeks to address the limitations of prior artsystems, by providing substantially predictable positioning andalignment, both translationally and rotationally within the vessel,while retaining a small profile and eliminating wire crossing so as toprovide ease of delivery. Several different embodiments of the inventionprovide solutions for different types of lesions, as will be describedin further detail hereinbelow.

Lesion Type 1, Type 2 and Type 4

In a first embodiment, a stent delivery system 10 is designed to bedelivered at a Type 1, Type 2 or Type 4 bifurcation lesion, asillustrated in FIGS. 29a, 29b and 29d , respectively. In these types ofbifurcation lesions, the plaque 4 is at least partially located withinthe main vessel in the vicinity of bifurcation point 3, and may also belocated within branch vessel 2.

Reference is now made to FIG. 3 and FIGS. 4a-d , which are illustrationsof a bifurcation stent delivery system 10, shown with and without astent respectively. System 10 includes a main elongated element 16, andan auxiliary elongated element 34 aligned with main elongated element16. In a preferred embodiment, auxiliary elongated element 34 ispositioned within main elongated element 16 proximal to an exit point 37and alongside main elongated element 16 distal to exit point 37, asdepicted in FIG. 3. In an alternative embodiment, auxiliary elongatedelement 34 is positioned alongside main elongated element 16, as will bedescribed hereinbelow with reference to FIG. 8.

In a preferred embodiment, main elongated element 16 is a catheter 18having a distal end 20 and a proximal end 22. A balloon 24 is positionedon distal end 20 of catheter 18. Catheter 18 includes a hypotube 25running along a proximal portion of the catheter, and an inflation lumenwithin hypotube 25 in communication with balloon 24. Hyoptube 25 iscomprised of stainless steel, or any other suitable material whichprovides rigidity. At a distal portion of catheter 18, a polymer jacketreplaces hypotube 25, providing flexibility for navigation through thevessel. The inflation lumen continues to run through the polymer jacketportion of catheter 18 and into balloon 24. The inflation lumen isdesigned for introducing a fluid, preferably a liquid, into balloon 24for inflation of balloon 24 at the appropriate location. A port forinflation is positioned at proximal end 22, in a configuration which iswell known in the art. Catheter 18 shown in FIGS. 3 and 4 a-d may be anycommercially available balloon catheter. Optionally, a torquer devicemay be introduced to proximal end 22 for improving torqueability. Suchtorquer devices are well known in the art, and may be purchased, forexample from Qosina Corp. (Edgewood, N.Y., USA, catalog part number97333).

In an exemplary preferred embodiment, balloon 24 is a fixed wire balloonand as such, includes a fixed wire 26 attached to a distal end ofballoon 24 at a bonding area 28. A core wire 30 (or skeleton) runs alongthe interior of balloon 24 to provide rigidity to the flexible portionof catheter 18. In a preferred embodiment, core wire 30 is acontinuation of fixed wire 26. It is a particular feature of the presentinvention that core wire 30 is connected at a proximal end thereof tohypotube 25, at a distal end thereof to the distal end of balloon 24,and in at least one other location in between. Referring again to FIGS.4a and 4c , core wire 30 is bonded to catheter 18 at an area of crosssection B-B, where side branch lumen 36 exits catheter 18. Furthermore,core wire 30 is relatively thick as compared to a filament which ispresent within commercially available fixed wire balloons. Suchfilaments are typically within a range of 0.005 to 0.009 inches (mostcommonly around 0.007 inches), while the core wire 30 of the presentinvention is in a range of 0.009-0.012 inches (most preferably around0.01 inches). This thickness, along with additional bonding of core wire30 to catheter 18, provides rigidity along an entire length of catheter18. This rigidity allows transmission of torque forces from proximal end22 to distal end 20 of catheter 18, and minimal loss of such forces dueto bending or twisting of the polymer jacket, thus providing enhancedtorqueability of the system. Furthermore, the rigidity provided by corewire 30 and the features described above provide enhanced pushingcapability of the system of the present invention, by preventingabsorption of pushing forces by the polymer jacket or by otherrelatively compliant portions of system 10.

System 10 includes a stent 12 positioned on main elongated element 16,the stent 12 having a side opening 14. In one embodiment, side opening14 is a dedicated side opening, and in another embodiment, side opening14 is any opening within the structure of stent 12. For example, a stenthaving a diamond configuration of struts might not require a dedicatedside opening, as any cell may be used to access the branch vessel. In apreferred embodiment, auxiliary elongated element 34 is a side branchlumen 36 for placement of a side branch guidewire therethrough. Sidebranch lumen 36 has a distal end 40 and a proximal end 42 and isattached to catheter 18 at proximal end 42 and unattached to catheter 18at distal end 40. The point at which the detachment between main andauxiliary elongated elements (catheter 18 and side branch lumen 36 inthe present embodiment) occurs is defined as a crotch point 44. In analternative embodiment, side branch lumen 36 is unattached to catheter18 both proximal and distal to crotch point 44, and is attached tocatheter 18 only at crotch point 44. Core wire 30 further includesfluorescent markers 32 which can be visualized during a procedure underfluorescence. In a preferred embodiment, markers 32 are aligned witheach end of stent 12 and with crotch point 44, forming a row of markers.In an exemplary preferred embodiment, an additional marker is includedat distal end 40 of side branch lumen 36. This configuration provides aview of the rotational alignment of system 10 within the vessel. Adiscussion of marker configuration and alignment is discussed in moredetail hereinbelow with respect to FIGS. 27a-d and 28. In alternativeembodiments, any configuration of markers which would enable viewing ofkey locations of system 10 can be used.

Crotch point 44 is preferably located close to distal end 40 of sidebranch lumen 36. It should be noted that the depiction of crotch pointsin the figures is for indication purposes only, and that crotch pointsmay not include an actual connecting element as shown. The length of theunattached portion is preferably less than 1 mm. In an exemplarypreferred embodiment, the length of the unattached portion isapproximately 0 mm, i.e. the distal end 40 of side branch lumen 36 is atcrotch point 44. It should be noted that in this embodiment, a guidewirewithin side branch lumen 36 is configured to enter a side branch vessel,as will be described hereinbelow with reference to FIG. 5. Thisguidewire positioned within side branch lumen 36, and main elongatedelement 16 form crotch point 44. In an alternative embodiment, thelength of the unattached portion is approximately 1-5 mm, or morepreferably approximately 2 mm. Side branch lumen 36 may be as long or asshort as necessary, both proximally and distally. In a preferredembodiment, the portion of side branch lumen 36 which is proximal tocrotch point 44 is approximately 10-30 mm, and in an exemplary preferredembodiment is approximately 25 mm. By extending side branch lumen 36proximally along at least a portion of hypotube 25, the rigidity ofsystem 10 is increased, thus providing ease of rotation within thevessel. In an alternative embodiment, the portion of side branch lumen36 which is proximal to crotch point 44 is approximately 5-15 mm.

Cross-sectional views along lines A-A, B-B and C-C are depicted in FIGS.4b, 4c and 4d , respectively. As shown in FIG. 4b , at a proximallocation, side branch lumen 36 is located within catheter 18. Core wire30 is in the center, and side branch lumen 36 is between core wire 30and the edge of catheter 18. As shown in FIG. 4c , at exit point 37,side branch lumen 36 is bonded to catheter 18. Distal to exit point 37,side branch lumen 36 is outside and adjacent to balloon 24, as shown inFIG. 4 d.

Reference is now made to FIG. 5, which is an illustration of system 10positioned at a bifurcation. Crotch point 44 is a key element inpositioning of stent 12 within the vessel. With catheter 18 in mainvessel 1 and a side branch guidewire 38 within side branch lumen 36positioned in branch vessel 2, system 10 cannot be advanced beyond thepoint at which crotch point 44 reaches bifurcation point 3. Thus, system10 is substantially predictably aligned, and overshooting is prevented.Side branch guidewire 38 is chosen to have optimal stiffness. In apreferred embodiment, guidewire 38 has an intermediate stiffness, suchthat it is stiff enough to guide system 10 and to prevent system 10 fromadvancing beyond crotch point 44, but not too stiff so as to riskpuncturing the vessel.

In an exemplary preferred embodiment, a method for introducing system 10is as follows. First, a side branch guidewire 38 is positioned withinbranch vessel 2. A proximal end of side branch guidewire 38 isintroduced into distal end 40 of side branch lumen 36. With side branchguidewire 38 positioned within side branch lumen 36, system 10 isadvanced through main vessel 1. Fixed wire 26 provides guidance asadvancement occurs. In an alternative embodiment, side branch guidewire38 is not introduced initially, and system 10 is advanced using onlyfixed wire 26 as a guide. In this embodiment, side branch guidewire 38is initially backloaded into side branch lumen 36 and remains withinside branch lumen 36 as system 10 is advanced through main vessel 1. Ineither case, system 10 is free to rotate without risk of entanglement.When crotch point 44 reaches bifurcation point 3, advancement of system10 automatically stops. At this point, system 10 is in place, with sidebranch guidewire 38 in branch vessel 2, and stent 12 in a correctposition both translationally and rotationally. Balloon 24 is theninflated, thus deploying stent 12 within the vessel. Thus, the exactlocation of crotch point 44 predetermines accuracy of positioning. Afterdeployment, system 10 is removed from branch vessel 2. A particularfeature of the invention as described is the ability to provide rapidexchange of catheters via branch guidewire 38, if necessary.

It should be apparent that the specific features of the presentinvention allow for accurate positioning in both the rotational and thetranslational direction, while providing a small outer diameter overall.In a preferred embodiment, the overall outer diameter is 0.5-1.5 mm.Specifically, by attaching side branch lumen 36 directly to balloon 24,for example, and predetermining the location of crotch point 44, sidebranch lumen 36 acts as a guide in the translational plane. The use of afixed wire provides torqueability and ease of rotation, particularlysince there is only one guidewire present (i.e. the branch guidewire).The presence of a bonded, relatively thick core wire 30 providesrigidity and ease of transmission of torque and pushing forces. Theconfiguration of side branch lumen 36 wherein a distal end 40 thereof isunattached to main elongated element 16, or wherein a guidewire placedtherethrough is unattached to main elongated element 16 allows forinitial entry of side branch lumen 36 into branch vessel 2. Theseaspects allow for substantially predictable rotation of the system andsubstantially predictable rotational positioning, without wireentanglement.

In one embodiment, the system 10 illustrated in FIGS. 3, 4 a-d and 5 isconfigured for use in treating an intracranial aneurysm. Current methodsfor treating such aneurysms include the use of self-expanding stentssuch as, for example, the Neuroform™ stents manufactured by BostonScientific Corp. (MA, USA). Specifically, such stents are presented tothe site of the aneurysm and deployed, after which a standardmicrocatheter is introducible through openings of the deployed stent. Anembolic coil is introduced into the aneurysm through the microcatheterto plug the site of the aneurysm. Self expanding stents are generallyused due to their low profile and maneuverability, features which arecrucial for small vessels associated with intracranial aneurysms.However, they are prone to positioning problems and are difficult toanchor in place during deployment. A system such as the one described inpreferred embodiments of the present invention can be used in place ofself expanding stents for treatment of aneurysms, and provide both thebenefits of small profile and maneuverability as well as betterpositioning and anchoring.

Reference is now made to FIGS. 30A-30E, which are illustrations of stepsof a method for treating an intracranial aneurysm in accordance with oneembodiment of the present invention. As shown in FIG. 30A, system 10 isintroduced into a vessel 200 with an aneurysm 202, and positioned suchthat side opening 14 of stent 12 is situated at the site of theaneurysm, as shown in FIG. 30B. Alternatively, a stent without a sideopening may be used. Positioning may be done by using markers and/or bythe introduction of guidewire 38 through side branch lumen 36. Once thesystem is in place, stent 12 is deployed, as shown in FIG. 30C. Catheter18 is removed, leaving stent 12 and guidewire 38 in place at the site ofthe aneurysm, as shown in FIG. 30D. As shown in FIG. 30E, a standardmicrocatheter 204 is then introduced over guidewire 38 through sideopening 14 and into the area of the aneurysm, through which an emboliccoil 206 may be delivered to the site.

Reference is now made to FIG. 6, which is an illustration of system 10in accordance with an alternative embodiment of the present invention.As shown in FIG. 6, system 10 further includes a distal connectingelement 46, attached to a distal end of balloon 24. In a preferredembodiment, distal connecting element 46 is attached at bonding area 28of balloon 24. In an alternative embodiment, distal connecting element46 is attached at any other location on balloon 24 which is distal toside branch lumen 36. Distal connecting element 46 is configured to holdside branch guidewire 38 in place until system 10 is in the vicinity ofbifurcation 3. This prevents side branch guidewire 38 from moving aroundwithin the vessel during delivery of system 10, possibly causing damage.Once system 10 is within the general vicinity of bifurcation 3, sidebranch guidewire 38 is pulled proximally and released from distalconnecting element 46, after which it is advanced into branch vessel 2.System 10 is then advanced until crotch point 44 prevents furtheradvancement, balloon 24 is inflated, and stent 12 is deployed.

Reference is now made to FIG. 7, which is an illustration of system 10in accordance with yet another embodiment of the present invention. Asshown in FIG. 7, side branch lumen 36 is located internally withinballoon 24, and includes an exit point 37 at a location along balloon24. The location of exit point 37 with respect to stent 12 defines acrotch point, which coincides with the location of crotch point 44described in the earlier embodiments, and is functionally equivalentthereto. In one embodiment, side branch lumen 36 ends at crotch point44. In an alternative embodiment, side branch lumen 36 extends distallybeyond crotch point 44.

Reference is now made to FIG. 8, which is an illustration of system 10in accordance with yet another embodiment of the present invention. Sidebranch lumen 36 is located external and adjacent to main elongatedelement 16. Crotch point 44 is located distal to an attachment pointbetween side branch lumen 36 and balloon 24. The portion of side branchlumen 36 which lies between the attachment point and crotch point 44 maybe attached or unattached to balloon 24.

Reference is now made to FIGS. 9a and 9b , which are illustrations ofsystem 10 in accordance with yet another embodiment of the presentinvention, shown with a stent thereon. In this depiction, side hole 14is not a dedicated side hole, but rather is any opening within the bodyof stent 12. It should be noted that this type of stent may be includedon any of the embodiments described herein. System 10 includes a mainguidewire 39 rather than a fixed wire at the distal end of balloon 24. Amain guidewire lumen 50 is located at bonding area 28 of balloon 24. Ina preferred embodiment, main guidewire lumen 50 is relatively short,i.e. 1-5 mm. In alternative embodiments, main guidewire lumen 50 extendsproximally along a side of balloon 24. In a preferred embodiment, mainguidewire 39 is positioned outside of stent 12 so as to avoid wirecrossing between main guidewire 39 and side branch guidewire 38, asshown in FIG. 9a . In an alternative embodiment, main guidewire 39 ispositioned within stent 12, as shown in FIG. 9b . In a preferredembodiment, main guidewire lumen 50 is positioned on an opposite sidefrom side branch lumen 36, as depicted.

In an alternative embodiment (not shown) of the present invention,system 10 includes a main guidewire lumen in place of a fixed wire, andfurther includes a crotch point 44 in accordance with the differentembodiments described above.

The embodiment shown in FIG. 9b allows for main guidewire 39 to be fixedduring insertion and movable after inflation of balloon 24. In oneembodiment, main guidewire 39 is fixed during insertion by crimping of astent thereon. In another embodiment, balloon 24 is formed to holdguidewire 39 therein prior to inflation and to release guidewire 39following inflation. The configuration of balloon 24 forms a “temporarylumen,” defined as a lumen which is present on balloon 24 only in adeflated state. That is, inflation of balloon 24 causes balloon 24 tounfold, resulting in a disappearance of the temporary lumen and releaseof guidewire 39. Reference is now made to FIGS. 31a and 31b , which arecross-sectional illustrations of system 10 showing balloon 24 in adeflated state with main guidewire 39 positioned within a temporarylumen 27, in accordance with embodiments of the present invention. Asshown in FIG. 31A, balloon 24 is folded in an “S” shape having acontainment area 80 in one of the curved portions of the “S” shape. Mainguidewire 39 is positioned in containment area 80, while auxiliaryelongated element 34 is positioned outside of balloon 24. Stent 12 ispositioned around balloon 24, main guidewire 39 and auxiliary sidebranch lumen 36. In another embodiment, shown in FIG. 31B, balloon 24 isfolded in a hooked “Y” shape, wherein the bottom portion of the “Y”shape is curved to form a containment area 82. The portion of the “Y”shape determined by the two arms of the “Y” acts as a secondarycontainment area 84 for holding side branch lumen 36 therein.Containment area 80 or 82 acts as a temporary lumen 27, at leastpartially containing main guidewire 39 therein until inflation ofballoon 24. Stent 12 is positioned around balloon 24, main guidewire 39and side branch lumen 36.

In this embodiment, side branch lumen 36 is a guidewire enclosure forplacing of a guidewire therethrough. In a preferred embodiment theguidewire enclosure is at least partially attached to the catheter atthe crotch point. In a preferred embodiment, the guidewire enclosure isat least partially positioned within the catheter body so as to minimizethe outer profile of the catheter. The distal end of the guidewireenclosure can be located at or distal to the attachment point.

In a preferred embodiment, a guidewire lumen 50 is attached to theballoon distal end, and has a length of less than 15 mm. The containmentarea 80 or 82 forming temporary lumen 27 is preferably longitudinallyaligned with the guidewire lumen, such that a distal end of theguidewire is positionable through the guidewire lumen and a portion ofthe guidewire which is proximal to the distal end of the guidewire ispositionable in the temporary lumen 27. In a preferred embodiment, thetemporary lumen 27 and the guidewire lumen are on an opposite side fromthe guidewire enclosure. According to additional features, the guidewireenclosure is at least partially positioned within said catheter body andis attached to the catheter body at a location on the balloon. Thelocation is approximately in a center of the balloon.

During a procedure, the catheter system with guidewire 39 positionedthrough guidewire lumen 50 and in temporary lumen 27 is introduced intothe vessel. Upon inflation of the balloon, guidewire 39 is released fromtemporary lumen 27, and becomes movable with respect to the catheter. Ina preferred embodiment, a housing positioned proximal to a proximal endof temporary lumen 27 holds a portion of guidewire 39 in place.Furthermore, a torquer may be placed at a proximal end of the catheter.The method provides the benefits of a fixed wire, with the additionalbenefit of a second guidewire positioned in the vessel during theprocedure.

Lesion Types 4A and 4B

In a second embodiment, a stent delivery system 110 is designed to bedelivered at a Type 4A or 4B bifurcation lesion as illustrated in FIGS.29e and 29f . In a Type 4A lesion, plaque 4 is located in branch vessel2, at or near bifurcation 3. In a Type 4B lesion, plaque 4 is located inmain vessel 1 distal to the point of bifurcation 3. One example of sucha location is the coronary artery, where blockage of, for example, theleft anterior descending (LAD) artery is to be avoided while providingcoverage to the plaque within the coronary artery. Other examplesinclude renal arteries, the left main coronary artery, vein grafts, andothers.

Reference is now made to FIGS. 11a-c , which are illustrations ofdifferent embodiments of a system 110 for delivery of a stent at a Type4A or Type 4B bifurcation lesion. System 110 may be designed with afixed wire, as shown in FIG. 11a , as on over-the-wire system, as shownin FIG. 11b , or as a rapid exchange system, as shown in FIG. 11 c.

Reference is now made to FIG. 11a , which is an illustration of system110 designed as a single wire system. System 110 includes a mainelongated element 116 and an auxiliary elongated element 134. In apreferred embodiment, main elongated element 116 is a catheter 118. In apreferred embodiment, catheter 118 includes a balloon 124 with a fixedwire 126 at a distal end thereof. A stent 112 is positioned on balloon124. In a preferred embodiment, auxiliary elongated element 134 is aside branch lumen 136, and is attached to catheter 118 at a crotch point144. Side branch lumen 136 has a proximal end 142 and a distal end 140.In a preferred embodiment, side branch lumen 136 is positioned withincatheter 118 proximally, exits at an exit point 137, and is attached tomain elongated element 116 at crotch point 144. The portion of sidebranch lumen 136 between exit point 137 and crotch point 144 may beattached or unattached. In a preferred embodiment, a distal end of sidebranch lumen 136 is at crotch point 144, and a guidewire placedtherethrough extends distally to provide a stopping point. In analternative embodiment, the distal end of side branch lumen is located1-5 mm distal to crotch point 144, and is unattached to the catheter 118in this location.

In an alternative embodiment, side branch lumen 136 is located externalto and positioned alongside catheter 118 proximal to crotch point 144,and is unattached to elongated element 116 distal to crotch point 144.In an alternative embodiment, side branch lumen 136 is unattached tocatheter 118 both proximal to and distal to crotch point 144. Crotchpoint 144 is located at or near a proximal end of stent 112. In apreferred embodiment, crotch point 144 is just proximal to the proximalend of stent 112.

Reference is now made to FIG. 11b , which is an illustration of system110′ designed as an over-the-wire, double rail system. System 110′ issimilar to system 110 shown in FIG. 11a , except that in place of afixed wire on the distal end of balloon 124′, a main guidewire lumen 125is present and runs the length of catheter 118′. A main guidewire ispositioned through main guidewire lumen 125 for entry into main vessel1. System 110′ may be introduced to the site via a main guidewirelocated in main guidewire lumen 125 or via a branch guidewire located inside branch lumen 136′.

Reference is now made to FIG. 11c , which is an illustration of system110″, designed as a rapid exchange dual wire system. System 110″ issimilar to both systems 110 and 110′ depicted in FIGS. 11a and 11c ,except that in place of a fixed wire or a main guidewire lumen runningthe length of catheter 118″, a short main guidewire lumen 127 is presentand runs proximally until an exit point 129. These types of systems arewell known in the art, and are known to provide ease of catheterexchange. In the present invention, the location of crotch point 144allows for more accurate placement within the vessel.

Reference is now made to FIG. 12, which is a depiction of system 110positioned at bifurcation 3 for a Type 4B lesion. A side branchguidewire 138 is introduced into branch vessel 2. System 110 is guidedover side branch guidewire 138 and either fixed wire 126 or a mainguidewire 139, depending on the type of system, until crotch point 144of side branch lumen 136 is at bifurcation point 3. In a preferredembodiment, distal end 140 is at crotch point 144, and only guidewire138 enters branch vessel 2. In an alternative embodiment, side branchlumen 136 extends and into side branch vessel 2. System 110 is slowlyadvanced until crotch point 144 reaches bifurcation point 3, after whichsystem 110 automatically stops advancing. Balloon 124 is then inflated,deploying stent 112. After deployment, balloon 124 is deflated, andsystem 110 is removed. For a Type 4A lesion, a similar method would beused, but side branch guidewire 138 would be introduced into main vessel3, and system 110 would be guided into branch vessel 2.

In an alternative embodiment, system 110 is a catheter system and doesnot include a stent, as shown in FIG. 32. Crotch point 144 is anattachment point which is located at or near a proximal end of balloon124, rather than at or near a proximal end of stent 112. Morespecifically, balloon 124 includes a working length portion 146, aproximal narrowed portion 148, and a distal narrowed portion 149.Working length portion 146 is defined as the portion of balloon 124 withthe largest outer diameter, while proximal and distal narrowed portions148, 149 are the portions of balloon 124 which have a smaller diameterthan working length portion 146. In one embodiment, crotch point 144 isproximal to working length portion 146, and in some embodiments islocated at a junction where working length portion 146 meets up withproximal narrowed portion 148. Auxiliary elongated element 134 is aguidewire enclosure for placing of a guidewire therethrough. In apreferred embodiment the guidewire enclosure is at least partiallyattached to the catheter at the crotch point. In a preferred embodiment,the guidewire enclosure is at least partially positioned within thecatheter body so as to minimize the outer profile of the catheter. Thedistal end of the guidewire enclosure can be located at or distal to theattachment point. It should be readily apparent that a core wire 130 maybe positioned through balloon 124 to attach the fixed wire 126 to ahypotube of the catheter, providing rigidity throughout system 110.

Reference is now made to FIGS. 33A-33G, which are schematicillustrations of a system 710 without a stent, in accordance withanother embodiment of the present invention. System 710 includes a mainelongated element 716, which in embodiments of the present invention isa catheter shaft, and a core wire 730 attached to main elongated element716 and positioned therethrough. At a core wire exit point 743, locatedat some point along main elongated element 716, core wire 730 exits thecatheter shaft so that it is positioned outside of main elongatedelement 716, and is termed an external core wire 731.

In one embodiment, core wire exit point 743 is at a distal end of mainelongated element 716. In other embodiments, core wire exit point 743 isat other locations along main elongated element 716. A balloon 724 ispositioned at the distal end of main elongated element 716, and is influid communication with an internal portion of main elongated element716, either via a designated inflation lumen or in a configurationwherein the internal portion of main elongated element 716 acts as aninflation lumen. Balloon 724 can be made of a variety of diameters,ranging from 1.25-10.0 mm, for example. A fixed wire 726 is positionedon the distal end of balloon 724. In one embodiment, balloon 724 is afixed wire balloon as is commonly known in the art. An example of such aballoon is the type used for the Ace Balloon Catheter of BostonScientific Corporation (Natick, Mass., USA). In another embodiment,balloon 724 is any balloon with a fixed wire attached thereto. Externalcore wire 731 runs alongside balloon 724, and is connected to fixed wire726 at a distal portion of balloon 724. In one embodiment, core wire730, external core wire 731 and fixed wire 726 are all comprised of thesame wire. In another embodiment, some or all of core wire 730, externalcore wire 731 and fixed wire 726 are separate pieces of wire which areconnected at particular locations. In either case, several attachment orbonding locations provide transmission of forces through the length ofthe catheter, and thus enhance overall torquability and rotatability. Inparticular, bonding can be done at any or all of the followinglocations: at a distal tip of balloon 724, at core wire exit point 743,and at an internal attachment point 745, which is a location within mainelongated element 716 at which core wire 730 is attached to mainelongated element 716. In embodiments of the present invention, mainelongated element is comprised of a hypotube, and core wire 730 isattached to the hypotube. Additional attachment points may be includedas well. External core wire 731 further includes markers 732 forvisualization.

In the embodiment shown in FIG. 33A, auxiliary elongated element 734 hasan exit point 729 for rapid exchange. At least a portion of auxiliaryelongated element 734 is positioned inside main elongated element 716,and also has a distal exit point 737 for a guidewire 739 placedtherethrough. In one embodiment, guidewire 739 positioned through distalexit point 737 forms a crotch point 744 at or near a proximal end ofballoon 724. The presence of a crotch point may be useful, for example,for anchoring system 710 within a side branch to avoid slippage withinthe vessel to be treated. In FIG. 33B, balloon 724 is shown in itsexpanded state. As shown, external core wire 731 is positioned alongsideballoon 724, and provides an area of focused force for cracking orbreaking up hard or difficult lesions. In one embodiment, an additionalguidewire 739 positioned through auxiliary elongated element 734 can beused to provide an additional area of focused force. In someembodiments, additional guidewire 739 is positioned at a rotationaldistance from external core wire 731 so as to provide multiple areas offocused force around system 710. For example, auxiliary elongatedelement 734 may be positioned approximately 180 degrees from externalcore wire 731, although it should be readily apparent that manydifferent rotational distances are possible.

Reference is now made to FIG. 33C, which is a cross-sectionalillustration of a portion of system 710 which is proximal to core wireexit point 743. As shown in FIG. 33C, main elongated element 716includes an inflation area or a designated inflation lumen 720, which isin fluid communication with balloon 724 and provides fluid thereto forinflation of balloon 724. Fluid is introducible through an inflationport 752, located at the proximal end of main elongated element 716.Auxiliary elongated element 734 is positioned within main elongatedelement 716. Core wire 730 can be positioned anywhere within mainelongated element 716, and more specifically may be positioned withininflation lumen 720.

Reference is now made to FIGS. 33D-33F, which are cross-sectionalillustrations of a portion of system 710 through balloon 724, withballoon 724 shown in an unexpanded state according to two embodiments inFIGS. 33D and 33E, and in an expanded state in FIG. 33F. As shown,balloon 724 is folded in its unexpanded configuration. External corewire 731 is positioned within folds of balloon 724. If a guidewire 739is present, guidewire 739 can be seen alongside balloon 724. As shown inFIG. 33F, when balloon 724 is expanded, external core wire 731 ispositioned alongside balloon 724. Guidewire 739 is also positionedalongside balloon 724, in a different location around the circumferenceof the balloon. It should be readily apparent that the use of guidewire739 is optional. In addition, the entire system 710 may be fabricatedwithout an auxiliary elongated element, wherein external core wire 731is relied on to provide the focused force.

Reference is now made to FIG. 33G, which is a cross-sectionalillustration of the portion of system 710 including balloon 724, inaccordance with another embodiment. In this embodiment, several externalcore wires 731, 733 and 735 are used. Although shown with three externalcore wires, any suitable number of core wires may be used. In oneembodiment, core wire 730 is split into multiple wires at core wire exitpoint 743, and the multiple core wires are bundled together at fixedwire 726.

Reference is now made to FIGS. 34A-34C, which are illustrations ofsystem 710 with an over-the-wire configuration. In this embodiment,there is no exit point 729 for rapid exchange. Rather, a guidewire port750 is positioned at a proximal end of main elongated element 716 andauxiliary elongated element 734 runs internally along the entire lengthof main elongated element 716. Guidewire port 750 and inflation port 752may be configured, for example, in a Y-configuration, as shown. As shownin FIGS. 34B and 34C, which are two embodiments showing a cross-sectionalong the shaft of system 710, auxiliary elongated element 734 andinflation lumen 720 run alongside one another, with core wire 730positioned alongside both auxiliary elongated element 734 and inflationlumen 720. It should be readily apparent that the relative positioningof auxiliary elongated element 734, inflation lumen 720 and core wire730 is variable, for example as shown in two variations in FIG. 34B andFIG. 34C, respectively.

A catheter system having a fixed wire balloon and auxiliary elongatedelement 734 such as described above may be beneficial in treating bothregular lesions and bifurcated lesions. For a non-bifurcated lesion, aguidewire is introduced into the vessel and through the lesion. Thecatheter is then advanced over the guidewire by introducing a proximalend of the guidewire into auxiliary elongated element 734. The catheteris advanced until it reaches the lesion, and is thus in a position suchthat the guidewire lies alongside the balloon. Upon inflation of theballoon, the guidewire is compressed into the lesion site, and providesa focused force to enable the user to crack hard lesions at low pressurebefore the balloon is fully inflated. Doing so allows vessel stretchingto occur at a lower strain rate, thus minimizing the trauma associatedwith balloon dilatation. The use of an external core wire 731 providesan additional focused force. Alternatively, instead of introducing aguidewire, fixed wire 726 is used to cross the lesion. In thisembodiment, auxiliary elongated element 734 may optionally not beincluded. Balloon 724 is then expanded, and external core wire 731provides the focused force. If auxiliary elongated element 734 ispresent, a guidewire 739 may additionally be introduced throughauxiliary elongated element 734 to provide additional focused force.These forces may be useful in treating a variety of lesions, includingthose found at renal or peripheral vessels, and may be useful forprocedures requiring high forces such as valvioplasty.

System 710 further provides a low profile carrier for appliances whichneed to be introduced distal to a lesion. Fixed wire 726 or guidewire739 is used to cross the lesion. Balloon 724 is then expanded, with thefocused force provided by external core wire 731, or by several externalcore wires or by guidewire 739 or any combination thereof. Once thelesion is cracked, system 710 can be positioned distal to the lesionarea. Auxiliary elongated element 734 is then available as a conduit forany additional items or appliances which are needed such as a guidewire,contrast media, or any other item which might have clinical utility.Such items may be readily placed through auxiliary elongated element734, and into the vessel at a point distal to the lesion.

The presence of a guidewire enclosure further provides an opportunity totreat lesions located at a bifurcation without reintroduction of thesystem. After treatment of a lesion in the first vessel, the guidewireis pulled back proximally and introduced into a second vessel which isconnected to the first vessel at a bifurcation. The balloon is deflated,the catheter is retracted along the guidewire, and introduced into thesecond vessel. The balloon is then inflated so as to compress the lesionin the second vessel.

In an alternative method, the guidewire is introduced into the secondvessel, the catheter is advanced over the guidewire past the bifurcationand into the first vessel. The first lesion is then treated by inflatingthe balloon and compressing the lesion. The balloon is deflated, thecatheter is retracted, and introduced into the second vessel such thatthe guidewire is positioned alongside the balloon. Upon inflation of theballoon, the guidewire is compressed into the lesion site, and providesa focused force to enable the user to crack hard lesions at low pressurebefore the balloon is fully inflated.

In an alternative embodiment, a stent delivery system 210 is designed tobe delivered at a bifurcation lesion such as the one illustrated in FIG.13, having a main vessel 1 and a branch vessel 2 at an angle withrespect to main vessel 1, and wherein plaque 4 is located in branchvessel 2 at an area of a bifurcation 3. In an exemplary preferredembodiment, main vessel 1 is an aorta.

Reference is now made to FIGS. 14a and 14b , which are views of a system210 in accordance with an embodiment of the present invention. System210 includes a main elongated element 216 and an auxiliary elongatedelement 234. In a preferred embodiment, main elongated element 216 is acatheter 218 having a proximal end 222 and a distal end 220. Catheter218 has a balloon 224 at distal end 220, with a stent 212 positionedthereon. In one embodiment, balloon 224 includes a main guidewire lumen227. In an alternative embodiment, balloon 224 is a fixed wire balloon,such as described with reference to the first and second embodiments,and shown at least in FIGS. 4a and 11a . In a preferred embodiment, mainguidewire lumen 227 extends only partially in the proximal directionalong catheter 218 and includes an exit point 229 for rapid exchange. Inan alternative embodiment, system 210 is an over-the-wire system andmain guidewire lumen 227 extends proximally to the proximal end ofcatheter 218. In a preferred embodiment, auxiliary elongated element 234is a positioning system 236, which will be described in further detailhereinbelow.

In a preferred embodiment, positioning system 236 includes a stopperelement 250 and an attachment mechanism 252. In a preferred embodiment,stopper element 250 is separate from attachment mechanism 252 andcomprises, for example, spring wires, flexible polymers, or any othermaterial which can be extended in a first configuration and which can befolded, sprung or otherwise positioned to act as a stopper in a secondconfiguration. In an alternative embodiment, stopper element 250 is partof attachment mechanism 252, but can also be extended in a firstconfiguration and positioned to act as a stopper in a secondconfiguration. In one preferred embodiment, stopper element 250 iscomprised of a shape memory metal such as, for example, Nitinol. In theembodiment described herein, spring wires are used as stopper element250, which are designed to lay substantially horizontal to catheter 218in their unextended positions and to coil or spring into a stopper uponrelease. Attachment mechanism 252 attaches the spring wires to mainelongated element 216 to form crotch points 244. In a preferredembodiment, attachment mechanism 252 is a jacket having a proximal end256 and a distal end 254. Attachment mechanism 252 at least partiallyencloses stopper element 250 (shown as spring wires), such that aproximal portion of stopper element 250 enclosed by attachment mechanism252 is relatively straight, and a distal portion of stopper element 250is unenclosed and able to move freely. Attachment mechanism 252 cancomprise any biocompatible material, and is preferably comprised of apolymer. In a preferred embodiment, crotch points 244 are located at aproximal end of balloon 224.

Reference is now made to FIG. 14b , which is a cross-sectional view ofsystem 210 along the lines A-A, in accordance with one embodiment.Catheter 218 has main guidewire lumen 227 for introduction of a mainguidewire 239. Surrounding catheter 218 is stopper element 250, which isheld in place by attachment mechanism 252.

Reference is now made to FIGS. 15a-b , which are illustrations of system210 partially enclosed within a holder 254. The purpose of holder 254 isto temporarily hold stopper element 250 in a substantially straightconfiguration until the area of bifurcation point 3 is reached. In apreferred embodiment, holder 254 is a peel-away device. When holder 254is in place, stopper element 250 is enclosed and lies approximatelyalong the plane of main elongated element 216. In the embodiment shownin FIGS. 15a and b , stopper elements 250 are straightened in the distaldirection, such that they run alongside stent 212. The area proximal tocrotch points 244 is shown in cross section in FIG. 15b , and includes amain guidewire lumen 227 within catheter 218, stopper elements 250enclosed within attachment mechanism 252, and holder 254 surroundingattachment mechanism 252.

Reference is now made to FIGS. 16a-b , which are illustrations of system210 partially enclosed within holder 254, in accordance with anotherembodiment of the present invention. In the illustration shown in FIGS.16a and b , stopper elements 250 are bent in a proximal direction, withholder 254 surrounding stopper elements 250 and holding them in place.That is, stopper elements 250 are folded over attachment mechanism 252.The area proximal to crotch points 244 is shown in cross section in FIG.16b , and includes a main guidewire lumen 227 within catheter 218,stopper elements 250 enclosed both within and outside of attachmentmechanism 252, and holder 254 surrounding attachment mechanism 252 andstopper elements 250.

Reference is now made to FIG. 17, which is a depiction of system 210within a guiding catheter 260. Guiding catheter 260 includes a proximalend 262, through which system 210 is introduced, and a distal end 264,which is open to a vessel. As system 210 is guided into proximal end 262of guiding catheter 260, holder 254 is removed, since stopper element250 will remain in place within guiding catheter 260. In a preferredembodiment, holder 254 is a peel-away system, wherein the outer wallsmay be peeled away and removed from the system while system 210 is beingintroduced into guiding catheter 260. This introduction is performedoutside of the body. In an alternative embodiment, holder 254 is asheath, which can be pulled back as system 210 is being introduced intoguiding catheter 260. Holder 254 can be any device for holding stopperelement 250 in place until system 210 is within guiding catheter 260.

Reference is now made to FIGS. 18a and 18b , which are depictions of amethod for introducing system 210 to a bifurcation in accordance with anembodiment of the present invention. Guiding catheter 260 with system210 positioned therein is introduced through main vessel 1 untilbifurcation point 3. Distal end 264 of guiding catheter 260 isvisualized using methods currently known in the art, such as, forexample, fluorescent markers. Once distal end 264 of guiding catheter260 is at the entrance to branch vessel 2, system 210 is advancedthrough distal end 264 of guiding catheter 260, as shown in FIG. 18a .As system 210 is advanced, stopper elements 250 are no longer held inplace by guiding catheter 260, and will spring or coil into their secondconfiguration, acting as stoppers, as shown in FIG. 18b . System 210 isthen advanced until stopper elements 250 prevent system 210 from furtheradvancement, as shown in FIG. 18c . At this point, system 210 isproperly positioned, and stent 212 is deployed.

Y-Bifurcation

In another embodiment, a stent delivery system 310 is designed to bedelivered at a bifurcation 3 as illustrated in FIG. 19, having aY-configuration. Main vessel 1 branches into two branch vessels: a firstbranch vessel 2 and a second branch vessel 2′, and plaque 4 is locatedin main and/or branch vessels at the area of bifurcation point 3.

Reference is now made to FIG. 20, which is an illustration of a stentdelivery system 310, in accordance with one embodiment of the presentinvention. System 310 includes a main elongated element 316 and anauxiliary elongated element 334. In a preferred embodiment, mainelongated element 316 is a catheter 318. Catheter 318 has a proximal end322 and a distal end 320. Proximal end 322 includes a hub 321 having aY-valve for dual inflation. Distal end 320 has two balloons: a proximalballoon 324 and a distal balloon 325. Each of proximal and distalballoons 324 and 325 is in fluid communication with its own inflationchannel. An outer inflation channel 335 communicates with proximalballoon 324 and an inner inflation channel 327 communicates with distalballoon 325. Outer inflation channel 335 is coaxial with inner inflationchannel 327. Alternatively, outer inflation channel 335 and innerinflation channel 327 are positioned side by side. In either case,balloons 324 and 325 may be inflated separately. In an alternativeembodiment, outer inflation channel communicates with distal balloon 325and inner inflation channel 327 communicates with proximal balloon 324.In a preferred embodiment, distal balloon 325 has a fixed wire 326 at adistal end thereof. In alternative embodiments, system 310 includes amain guidewire lumen or a short external guidewire lumen such as distalconnecting element 50 shown in FIG. 6.

In a preferred embodiment, auxiliary elongated element 334 is a sidebranch lumen 336 having a proximal end 342 and a distal end 340. In apreferred embodiment, side branch lumen 336 is located internally withincatheter 318, and exits therefrom at an exit point 337. Distal to exitpoint 337, side branch lumen 336 is adjacent to proximal balloon 324 andattached thereto at a crotch point 344. In an alternative embodiment,side branch lumen 336 lies alongside proximal balloon 324.

Reference is now made to FIG. 21, which is an illustration of system 310with stents. In a preferred embodiment, two stents are included, asshown. A proximal stent 312 is positioned on proximal balloon 324, and adistal stent 313 is positioned on distal balloon 325. Each stent may beseparately deployed by inflating its corresponding balloon. Proximalstent 312 is positioned such that distal end of side branch lumen 336 isapproximately aligned with a distal end of proximal stent 312. Thedistal edges of side branch lumen 336 and stent 312 form a crotch point344. In an alternative embodiment, side branch lumen 336 extendsdistally past crotch point 344. All of the embodiments described earlierin the present application may further be applied here.

In alternative embodiments, system 310 includes one, two or no stents,depending on the application. For example, system 310 may be used forpredilatation, with a stent only on proximal balloon 324. Alternatively,a tapered vessel may require two different stent sizes, wherein onestent of a particular size is positioned on distal balloon 325, whileanother stent of a different size is positioned on proximal balloon 324.

Reference is now made to FIGS. 22a-d , which are illustrations of amethod of deploying system 310 within a Y-bifurcation. First, a sidebranch guidewire 338 is introduced into a first branch vessel 2. Aproximal end of side branch guidewire 338 is then placed through adistal end of side branch lumen 336. System 310 is advanced over sidebranch guidewire 38 through main vessel 1 and into second branch vessel2′. When crotch point 344 reaches bifurcation 3, system 310 will not beadvanceable, and system 310 will be in place, as shown in FIG. 22a . Asshown in FIG. 22b , distal balloon 325 is inflated via inner inflationchannel 327, deploying distal stent 313 in a branch vessel, just distalto bifurcation point 3. After deployment of distal stent 313, proximalballoon 324 is inflated via outer inflation channel 335, deployingproximal stent 312. An alternate method is depicted in FIG. 22c ,wherein proximal stent 312 is deployed first, and then distal stent 313is deployed. In an alternative embodiment, both stents are deployedsimultaneously. The final result with both stents deployed and inposition is shown in FIG. 22 d.

Reference is now made to FIG. 23, which is an illustration of a taperedballoon system 410, in accordance with an alternative embodiment of thepresent invention. Similar to the earlier embodiments, tapered balloonsystem 410 includes a main elongated portion and an auxiliary elongatedelement 434. In a preferred embodiment, auxiliary elongated element 434is a side branch lumen. A balloon has a proximal outer diameter and adistal outer diameter which is different from the proximal outerdiameter. In a preferred embodiment, the distal outer diameter issmaller than the proximal outer diameter, although the reverse may beprovided as well. This type of balloon system may be useful forintroduction of a tapered stent into a vessel, so as to avoidover-expansion of a stent within a distal portion of the vessel.

Lesion Type 3

In another embodiment, a stent delivery system 510 is designed to bedelivered at a Type 3 bifurcation lesion as illustrated in FIG. 29c . Ina Type 3 lesion, plaque 4 is located in main vessel 1, proximal to thepoint of bifurcation 3. Stent delivery system 510 is also suitable to bedelivered at a lesion in a non-bifurcated vessel, as will be describedmore fully hereinbelow.

Reference is now made to FIGS. 24a-c , which are illustrations ofdifferent embodiments of a system 510 for delivery of a stent at a Type3 bifurcation lesion. System 510 may be designed with a fixed wire, asshown in FIG. 24a , as on over-the-wire system, as shown in FIG. 24b ,or as a rapid exchange system, as shown in FIG. 24 c.

Reference is now made to FIG. 24a , which is an illustration of system510 designed as a single wire system. System 510 includes a mainelongated element 516 and an auxiliary elongated element 534. In apreferred embodiment, main elongated element 516 is a catheter 518. In apreferred embodiment, catheter 518 includes a balloon 524 with a fixedwire 526 at a distal end thereof. A stent 512 is positioned on balloon524. In a preferred embodiment, auxiliary elongated element 534 is aguidewire lumen 536, and is attached to catheter 518 at a crotch point544. Guidewire lumen 536 has a proximal end 542 and a distal end 540.Crotch point 544 is located at distal end 540. In a preferredembodiment, guidewire lumen 536 is positioned within catheter 518proximally, exits at an exit point 537, and is attached to mainelongated element 516 at crotch point 544. The portion of guidewirelumen 536 between exit point 537 and crotch point 544 may be attached orunattached. In a preferred embodiment, a distal end of guidewire lumen536 is at crotch point 544, and a guidewire placed therethrough extendsdistally to provide a stopping point. In an alternative embodiment, thedistal end of guidewire lumen is located 1-5 mm distal to crotch point544, and is unattached to the catheter 518 in this location.

In one embodiment, guidewire lumen 536 is located external to andpositioned alongside catheter 518 proximal to crotch point 544, and isunattached to elongated element 516 distal to crotch point 544. In analternative embodiment, guidewire lumen 536 is unattached to catheter518 both proximal to and distal to crotch point 544. Crotch point 544 islocated at or near a distal end of stent 512. In a preferred embodiment,crotch point 544 is approximately 2-3 mm distal to the distal end ofstent 512.

Referring to FIG. 27a , in an exemplary preferred embodiment, balloon524 is a fixed wire balloon and as such, includes a fixed wire 526attached to a distal end of balloon 524 at a bonding area 528. A corewire 530 (or skeleton) runs along the interior of balloon 524 to providerigidity to the flexible portion of catheter 518. Core wire 530 is acontinuation of fixed wire 526. It is a particular feature of thepresent invention that core wire 530 is connected at a proximal endthereof to hypotube 525, at a distal end thereof to the distal end ofballoon 524, and in at least one other location in between.Specifically, core wire 530 is bonded to catheter 518 at an area whereguidewire lumen 536 exits catheter 518. Furthermore, core wire 530 isrelatively thick as compared to a filament which is present withincommercially available fixed wire balloons. Such filaments are typicallywithin a range of 0.005 to 0.009 inches (most commonly around 0.007inches), while the core wire 530 of the present invention is in a rangeof 0.009-0.012 inches (most preferably around 0.01 inches). Thisthickness, along with additional bonding of core wire 530 to catheter518, provides rigidity along an entire length of catheter 518. Thisrigidity allows transmission of torque forces from proximal end 522 todistal end 520 of catheter 518, thus providing enhanced torqueability ofthe system. Furthermore, the rigidity provided by core wire 530 and thefeatures described above provide enhanced pushing capability of thesystem of the present invention, by preventing absorption of pushingforces by the polymer jacket or by other relatively compliant portionsof system 510.

Reference is now made to FIG. 24b , which is an illustration of system510′ designed as an over-the-wire, double rail system. System 510′ issimilar to system 510 shown in FIG. 25a , except that in place of afixed wire on the distal end of balloon 524′, a main guidewire lumen 525is present and runs the length of catheter 518′. A main guidewire ispositioned through main guidewire lumen 525 for entry into main vessel1. System 510′ may be introduced to the site via a main guidewirelocated in main guidewire lumen 525 or via a branch guidewire located inguidewire lumen 536′.

Reference is now made to FIG. 24c , which is an illustration of system510″, designed as a rapid exchange dual wire system. System 510″ issimilar to both systems 510 and 510′ depicted in FIGS. 24a and 24c ,except that in place of a fixed wire or a main guidewire lumen runningthe length of catheter 518″, a short main guidewire lumen 527 is presentand runs proximally until an exit point 529. In the present invention,the location of crotch point 544 allows for more accurate placementwithin the vessel.

Reference is now made to FIG. 25, which is a depiction of system 510positioned at bifurcation 3 for a Type 3 lesion. A side branch guidewire538 is introduced into branch vessel 2. System 510 is guided over sidebranch guidewire 538 and either fixed wire 526 or a main guidewire 539,depending on the type of system, until crotch point 544 of guidewirelumen 536 is at bifurcation point 3. In a preferred embodiment, distalend 540 is at crotch point 544, and only guidewire 538 enters branchvessel 2. In an alternative embodiment, guidewire lumen 536 extends intoside branch vessel 2. System 510 is slowly advanced until crotch point544 reaches bifurcation point 3, after which system 510 automaticallystops advancing. Balloon 524 is then inflated, deploying stent 512.After deployment, balloon 524 is deflated, and system 510 is removed.

Reference is now made to FIG. 26, which is a depiction of system 510positioned at a non-bifurcated lesion within a vessel 600. In oneembodiment, a guidewire 610 is introduced into vessel 600 and throughthe lesion. System 510 is guided over guidewire 610 and fixed wire 526until catheter 518 reaches the lesion site. Location is determined bymarkers 532, as will be described more fully hereinbelow with respect toFIGS. 27a-d and 28. Balloon 524 is then inflated, deploying stent 512.After deployment, balloon 524 is deflated, and system 510 is removed. Byproviding a guidewire in the vessel which is held in a guidewire lumenhaving an exit port distal to the proximal end of catheter 518, a rapidexchange of catheters is possible if necessary. Furthermore, the systemcan be used in a direct stenting procedure, without the need forpredilatation, reducing the invasiveness of the procedure. In analternative embodiment, guidewire 610 is backloaded and housed inguidewire lumen 536, and system 510 is introduced into the vessel guidedby fixed wire 526. System 510 is suitable for crossing the lesion on itsown due to the rigidity provided by core wire 530. Once system 510 is inplace, guidewire 610 is advanced so that a backup wire is present at anddistal to the lesion (for rapid exchange capabilities, for example).Balloon 524 is then inflated, deploying stent 512. There are severaladvantages in using system 510 as a regular non-bifurcation stentdelivery system, over the typical delivery systems currently available.It is widely recognized that rapid exchange has certain advantages,including ease of delivery and ease of interchanging catheters ifnecessary. However, the presence of a bonded, relatively thick core wireallows for greater ease of rotation and transmission of torque forceswithout increasing overall diameter, which is advantageous duringdelivery of the system. Furthermore, in a direct stenting procedure,either guidewire 610 or fixed wire 526 is suitable for crossing thelesion. With fixed wire 526 crossing the lesion, stent 512 isautomatically in place.

Reference is now made to FIGS. 27a-d , which are illustrations of amarker configuration, in accordance with a preferred embodiment. Asshown in FIG. 27a , a first marker 630, a second marker 632 and a thirdmarker 634 are included on core wire 30, and are aligned with proximaland distal ends of stent 12 and with crotch point 44, respectively. Afourth marker 636 is positioned at crotch point 44, thus forming atriangle with first and second markers 630 and 632. As shown in FIG. 27b, when system 10 is in position, the relative locations of the threemarkers are consistent with the original configuration. That is, first,second and third markers 630, 632 and 634 are aligned, and fourth marker636 is off to one side. As shown in FIG. 27c , when system 10 is rotated90 degrees, all four markers are relatively in the same line. As shownin FIG. 27d , when system 10 is rotated 180 degrees, fourth marker 636is on the other side of first, second and third markers 630, 632 and634. In this way, it is possible to visualize the rotational alignmentof system 10 on a two-dimensional viewing screen. In addition, markers634 and/or 636 may be configured in a triangle or pointing shape, asdepicted in FIG. 28, pointing toward the branch access. This alsoprovides additional confirmation of correct positioning. Thus, properalignment at a bifurcation is ascertained when all the markers arecorrectly positioned with respect to one another, and when the pointingshaped marker points toward the branch.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art. Forexample, a self-expandable stent may be used in place of a balloonexpandable stent, in which case the catheter would not necessarily be aballoon catheter. Accordingly, it is intended to embrace all suchalternatives, modifications and variations that fall within the spiritand broad scope of the appended claims. All publications, patents andpatent applications mentioned in this specification are hereinincorporated in their entirety by reference into the specification, tothe same extent as if each individual publication, patent or patentapplication was specifically and individually indicated to beincorporated herein by reference. In addition, citation oridentification of any reference in this application shall not beconstrued as an admission that such reference is available as prior artto the present invention.

What is claimed is:
 1. A method for treating a lesion in a vessel, themethod comprising: providing a catheter having a fixed wire balloon,with a fixed wire attached to a distal end of the balloon and extendingdistally from the balloon, and a core wire positioned externallyalongside the balloon wherein the core wire fixedly attaches to thefixed wire distally from the balloon and wherein the core wire ispositioned internally to the catheter in a region proximal to theballoon; introducing said catheter into the lesion; and inflating theballoon so as to compress the core wire into the lesion.
 2. The methodaccording to claim 1, wherein said catheter further comprises anauxiliary elongated element positioned internally within said catheter,the method further comprising advancing an item through said auxiliaryelongated element and to a location which is distal to the lesion. 3.The method according to claim 2, wherein said item is a guidewire. 4.The method according to claim 1, wherein said catheter further comprisesan auxiliary elongated element positioned internally within saidcatheter, the method further comprising advancing a guidewire throughsaid auxiliary elongated element prior to said inflating the balloon. 5.The method according to claim 4, wherein the auxiliary elongated elementhas a distal exit point proximal to said fixed wire balloon.
 6. Themethod according to claim 4, wherein the auxiliary elongated element hasa distal exit point positioned at a rotational distance from said corewire.
 7. The method according to claim 1, wherein said catheter furthercomprises an auxiliary elongated element positioned internally withinsaid catheter, the method further comprising deflating said balloon andthereafter advancing a guidewire through said auxiliary elongatedelement.
 8. The method according to claim 1, wherein the catheterfurther comprises multiple core wires.
 9. A method for treating a lesionin a vessel, the method comprising: introducing a guidewire into thevessel and through the lesion; advancing a catheter along the guidewire,wherein the catheter comprises a fixed wire balloon, with the fixed wireextending distally from a distal end of the balloon, and an externalcore wire positioned alongside the balloon wherein the external corewire fixedly attaches to the fixed wire distally from the balloon andwherein the core wire is positioned internally to the catheter in aregion proximal to the balloon; positioning the balloon within thelesion; and inflating the balloon so as to compress the external corewire into the lesion.
 10. The method according to claim 9, wherein theguidewire is positioned alongside the balloon and is compressed into thelesion when the balloon is inflated.
 11. A method for treating a lesionin a vessel, the method comprising: providing a catheter having aballoon with a fixed wire extending distally from the balloon with anunexpanded state and an expanded state, and an external core wirepositioned alongside the balloon and within folds of the balloon in theunexpanded state wherein the external core wire fixedly attaches to thefixed wire distally from the balloon and wherein the core wire ispositioned internally to the catheter in a region proximal to theballoon; introducing said catheter into the lesion; and inflating theballoon so as to compress the external core wire into the lesion. 12.The method according to claim 11, wherein a guidewire is positionedalongside the balloon when the balloon is in the unexpanded state. 13.The method according to claim 12, wherein the guidewire and externalcore wire are positioned alongside the balloon when the balloon isinflated.
 14. The method according to claim 13, wherein the guidewire iscircumferentially spaced from the external core wire when the balloon isinflated.
 15. The method according to claim 11, wherein the catheterfurther comprises multiple external core wires.
 16. The method accordingto claim 15, wherein the multiple external core wires are split from asingle core wire.
 17. The method according to claim 1, wherein theexternal core wire is fixed to the catheter.
 18. The method according toclaim 1, wherein the catheter further comprises an internal core wire.19. The method according to claim 2, wherein the item is separated fromthe external core wire.